Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
2D air movement in room with heating and ventilation
Posted Oct 5, 2016, 6:04 a.m. EDT Fluid & Heat, Heat Transfer & Phase Change, Geometry, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 5.2 2 Replies
Please login with a confirmed email address before reporting spam
Hello,
Last week I took my first Comsol course so I am quite new to the programme.
I try to model a (simple) 2D model of a room with room heating (a steel heat source), ventilation and direct sunlight.
My goal is to see the air movement in the room over a certain time.
I have 2 questions:
1. What is the best way to model the sun? Right now I added a heat flux.
2. Could somebody help me finding a solution to the error message below?
Your help will be appreciated!
Thank you very much.
Yvonne
Undefined variable.
- Variable: comp1.spf.pA
- Geometry: geom1
- Domain: 1
Failed to evaluate Jacobian of expression.
- Expression: (comp1.ht.d*((-comp1.ht.C_eff)*comp1.Tt))*dvol
Failed to evaluate Jacobian of expression.
- Expression: (-comp1.ht.C_eff*comp1.Tt*test(comp1.T)*comp1.ht.d)*(dvol)
Last week I took my first Comsol course so I am quite new to the programme.
I try to model a (simple) 2D model of a room with room heating (a steel heat source), ventilation and direct sunlight.
My goal is to see the air movement in the room over a certain time.
I have 2 questions:
1. What is the best way to model the sun? Right now I added a heat flux.
2. Could somebody help me finding a solution to the error message below?
Your help will be appreciated!
Thank you very much.
Yvonne
Undefined variable.
- Variable: comp1.spf.pA
- Geometry: geom1
- Domain: 1
Failed to evaluate Jacobian of expression.
- Expression: (comp1.ht.d*((-comp1.ht.C_eff)*comp1.Tt))*dvol
Failed to evaluate Jacobian of expression.
- Expression: (-comp1.ht.C_eff*comp1.Tt*test(comp1.T)*comp1.ht.d)*(dvol)
Attachments:
2 Replies Last Post Oct 6, 2016, 5:28 a.m. EDT
Please login with a confirmed email address before reporting spam
Posted:
8 years ago
Hello,
This error for domain 1 (air outside the room?) is due to the fact that "Heat transfer in fluids" under ht interface is looking for absolute pressure to be defined by nitf1, which is the "Non-isothermal flow 1" node under the "Multiphysics" interface.
In nitf1, the fluid flow points to the "laminar flow (spf)" interface, which could give the pressure, except that you have defined the spf interface to not include domain 1.
-DW
This error for domain 1 (air outside the room?) is due to the fact that "Heat transfer in fluids" under ht interface is looking for absolute pressure to be defined by nitf1, which is the "Non-isothermal flow 1" node under the "Multiphysics" interface.
In nitf1, the fluid flow points to the "laminar flow (spf)" interface, which could give the pressure, except that you have defined the spf interface to not include domain 1.
-DW
Please login with a confirmed email address before reporting spam
Posted:
8 years ago
Thanks DW!